Cr^(4+):Ca_2GeO_4激光晶体生长及光谱性能

Growth and Spectral Properties of Cr^(4+):Ca_2GeO_4 Laser Crystal

采用助熔剂法生长了0.5%(质量分数,下同)Cr4+:Ca2GeO4激光晶体。用X射线衍射(X-ray diffractometer,XRD)、吸收光谱及荧光光谱研究了晶体的相组成和光谱性能。XRD分析表明,获得的晶体为低温γ-Ca2GeO4相,镁橄榄石结构,空间群为Pbam。光谱分析表明:Cr4+:Ca2GeO4晶体在600～800 nm范围内的吸收峰对应Cr4+的3A2→3T1能级跃迁;晶体在1 000～1 200 nm的近红外区域的弱吸收带归因于Cr4+离子的3A2→3T2能级跃迁。室温下0.5%Cr4+:Ca2GeO4晶体荧光光谱的最强荧光发射峰值位于1 317 nm处,这归属于Cr4+的3T2→3A2能级跃迁,荧光寿命为7.9μs,发射截面为4.61×10–19 cm2。

0.5% in mass Cr^4＋：Ca2GeO4 laser crystal was grown by the flux method,and the structure,spectral properties of the Cr4^＋：Ca2GeO4 crystal were investigated via X-ray diffractometer（XRD）,the measurements of absorption and fluorescent spectra.The results of XRD show that as grown crystal belongs to γ-Ca2GeO4 phase with forsterite structure,space group Pbam.The spectra indi-cate that the absorption bands at 600–800 nm attributed to the ^3A2→^3T1 level transition of Cr^4＋,and the weak near infrared absorption band at 1 000–1 200 nm of the Cr^4＋：Ca2GeO4 crystal is due to the ^3A2→^3T2 level transition of Cr^4＋.The strongest fluorescence emis-sion peak of the Cr^4＋：Ca2GeO4 at room temperature is located at 1 317 nm,which is due to the ^3T2→^3A2 transition of Cr^4＋.The fluo-rescence lifetime and emission cross-section of Cr^4＋：Ca2GeO4 crystal are 7.9 μs and 4.61 × 10^–19 cm^2,respectively.